This invention relates to a device for shutting off the flow of fluid, such as gaseous fuel, in case of emergency such as an earthquake or accidental leakage of explosive gas.
In the case of an earthquake or accidental leakage of explosive gaseous fuel, it is required to shut off the flow of the fuel from a supply pipe or tank without fail to avoid secondary accidents caused by explosion of the gaseous fuel. To this end, many fluid shut-off devices have been provided hitherto. However, most of them are complicated in structure, unreliable in operation or expensive in manufacturing cost.
Accordingly, an object of the present invention is to provide a fluid shut-off device which is very simple in structure, reliable in operation and inexpensive in manufacturing cost.
Another object of the present invention is to provide a fluid shut-off device which is operated by an earthquake and/or in connection with a detector for gas leakage.
A further object of the present invention is to provide a fluid shut-off device which can be reset very easily by one action from an operative shut-off position.
Still another object of the present invention is to provide a fluid shut-off device which is operated very accurately by a small supply of electric current and which can maintain the operated position without any further supply of electric current.